My first subwoofer. Peerless xls10 in passive radiator application

131183914

Member
2013-03-14 1:01 am
Hi.
It's my first audio project done ever. I designed and build it myself. Inspiration was taken from few other projects.
Driver - Peerless xls10
Passive Radiator - Scan Speak Discovery 10
Amplifier - custom build 300W into 4Ohm
Built of double 18mm MDF, Faux leather, Gloss Acrylic
Capacity 20 litres!
Tune to 21Hz

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Something is facing down... I can't tell what is what from the diagram, since I can't read that language, sorry. Looks like the active driver. Regardless, whatever is facing down will not long resist the effects of gravity upon the suspension. Rotating the design 90 degrees on axis would correct that... Also the interaction with the floor may or may not be beneficial depending on the room and the floor.

Forgot to say, it is a very attractive implementation...
 

131183914

Member
2013-03-14 1:01 am
Looks like the active driver. Regardless, whatever is facing down will not long resist the effects of gravity upon the suspension. Rotating the design 90 degrees on axis would correct that... Also the interaction with the floor may or may not be beneficial depending on the room and the floor.
Thanks. You're right and i'm fully aware of that. However down firing applications are quite common and I think my driver will keep its performance for a good while..
Clearance between floor and driver it's 85mm but will be extended to 100mm in total.
The only reson i decided to build downfiring subwoofer was to keep it in small capacity (20liters)
 
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the volume stays the same if the woofer fires out a side that is not facing down.

the usual method is to make the woofer front firing, so that it combines properly if it is used up to the midbass... but a side will still work, and then the PR can be on the opposite side or an adjacent wall...

fwiw, the higher the mass of the cone (lower the F3) the more difficult it is for the suspension to resist the gravitational force over time... common or not it is a problem...

Also, for equal diameter PR and woofer, the PR will run out of excursion before the woofer.... so its a good idea to go at least one diameter up or two... even with the larger excursion PRs available today. That would be like a 12" woofer ---> 18" PR.

Enjoy ur subwoofer!! :D

_-_-bear
 

131183914

Member
2013-03-14 1:01 am
the usual method is to make the woofer front firing, so that it combines properly if it is used up to the midbass... but a side will still work, and then the*PR*can be on the opposite side or an adjacent wall...
I thought about that.. but simply didn't like the idea of woofers mounted on the opposite sides.

Also, for equal diameter*PR*and woofer, the*PR*will run out of excursion before the woofer.... so its a good idea to go at least one diameter up or two... even with the larger excursion PRs available today. That would be like a 12" woofer ---> 18"*PR.*
How about an extra weight. According to my simulation adding extra 200g should solved that problem

Enjoy ur subwoofer!!*
Now i won't enjoyed unless i solve all problems
 
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whoops, thought I replied... hmmm where did it go?

adding mass to the PR lowers the resonant frequency, making the suspension need to work harder to keep it in place, also adding mass lowers the resonant frequency, increasing the excursion. So the combination of a 12" main driver and an 18" PR is useful since the 12" can't possibly move enough air IF it is tuned sufficiently low...

_-_-
 
I grabbed this old thread to share my first sub restauration project.

I made my sub perhaps in 2008, following very popular concept of Peerless XLS-10 and passive radiator in a small 25 liter box. I searched the net and finally copied the box somewhere. It has drivers side by side, a separate compartment for Hypex DS2.0 amp, and two compartments filled with sand. Passive has extra weight for 100 grams.Material is 27mm MDF and front baffle has additional 12mm sheet. Weight is approximately 45kg.

Then I didn't have any measurement gear, I had to trust the info in the net, including added weight. Recently the sub has been at my children's apartments, but now I got it back. Measurements were astonishing! Perhaps the suspension of passive unit has hardened, but even without added mass passive is not working for good. Yes it vibrates, but sum effect is zero.

Because Hypex DS2.0 has some eq, I will buy a second active XLS-10 unit and add it in series. Volume knob is usually at 9 o'clock so we have lots of power available.

Here speaker is upside down on doctor's table.
 

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Old topic, but i'm still surprised of how low and flat this sub goes, certainly given it's age. I was modelling a new sub, and wanted to compare it to my XLS 10 + PR. It's unbelievable how flat it still goes to 20Hz. It doesn't have the output of a 15" but it sure has the musicality.

the output is the only reason I'm building a new sub, but this oldie is a goodie...

did you in the meanwhile replace the passive radiator? I would just replace it (there is a dayton drop in replacement) as 2 active woofers won't go as low (which is the point of a subwoofer)